Method of generating and controlling pressure.



E. T. vouwe. METHOD'OF GENERATING AND CONTROLLING PRESSURE.

APPLICATION FILED DEC. 15. 1910.

Patented Dec. 28, 1915.

3 SQHEETS-SHEET 1.

, E.T.Y0UNG. 1 METHOD OF GENERATING AND commune PRE-SSURF.

APPLICATION FILED DEC. 15, I910- 4 1,165,826; Patentd Dec. 28, 1915.

a SHEETS-SHEET 2.

E. T. YOUNG.

METHOD OF GENERATING AND CONTROLLING PRESSURE.

APPL ICATIQN FILED DEC. 15. 1910.

1,165,826; Pafented D0028, 1915.

3 SHEETSSHEET 3.

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EDWARD '1. YOUNG. OF MILTON. MASSACHUSETTS.

METHOD OF GENERATING AND CONTROLLING PRESSURE.

sure. of which the following is a specificzr tion.

The present invention relates to a method of generating and controlling pressure and for present purposes is herein described as used in connection with internal combustion and other engines operating with fuel, preferably oil or other liquid fuel. In its broadest application, however. it is not limited to engines of this type.

The object of this method is to produce and control combustion in such a way that an engine may be run with a high degree of economy and efficiency with a complete combustion of the fuel and a prolonged maximum working pressure and without excessive maximum working pressure.

An engine adapted to carry out the method herein specified is described'in anapplication for Letters Patent of the United States. Serial No. 347,617, filed by me December 13. 1906, of which this application is a divi-- sion, and this method is an improvement upon that described in Letters Patent .of the United States No. 901.310, issued to me October 13. 1908. in which there is described the injection of fuel, preferably in' the form of a. fine. jet or spray of liquid into air which is moderately compressed but highly heated resulting in the immediate and complete combustion of the fuel so that no excessive pressure results.

I am aware that previously in engines of a well known type, the fuel has been injected into 'a body ofair of high temperature so as to be spontaneously ignited but in such engines the necessary temperature is secured by adegree of compression of the air necessarily so high as to entail working pressures such as to render the engine very expensive and bulky in proportion to the power de,

livered and practically to prohibit the construction of engines of the largest powers In the present invention, on the other hand,

Specification of Letters Iatent.

Patented Dec. 28, 1915.

Divided and this application filed December the heat necessary for ignition is supplied from the walls of the chamber, the moderate compression of the air not being in itself suliicient for the purpose.

My invention in this aspect. is to be clearly distinguished from the method practised in engines provided with heated chambers or bodies so located and constructed that the liquid fuel, when introduced, is projected against the surface of such heated chamber or body so as to be vaporized by contact with the hot metal and thereafter ignited when sufiicicnt air to form an explosive mixture is applied by the compressing stroke of the piston. Such engines are open to the serious objection that the fuel is not completely consumed. since its vaporization in this manner causes the deposition of a hard and refractory form of carbon on the vaporizing surfaces. necessitating the frequent removal of such deposits and involving a loss in economy equal to the heat value of the carbon so deposited. An engine of this class is necessarily an explosive engine with all its attending disadvantages. In carrying out the present invention the fuel is so injected into a body of heated air that the fuel is ignited and entirely consumed as it enters.

The fuel is not fully'introduced at or before the commence rent of the working stroke. but is introduced gradually during a substantial portion of the working stroke. so as to maintain during such period a substantially uniform working pressure. thereby securing high eiliciency without excessive maximum pressure and temperature.

In order that the full advantages of my present method may be secured it is necessary that the fuel be injected in sufliciently increasing quantity to compensate for the increasing speed of the piston. so that a sub stantially constant pressure is maintained under an increasing rate of expansion. As the working medium expands the maximum pressure would decrease. The predetermined maximum working pressure. however. should be maintained during any de sired portion of the working stroke of piston, and as the piston velocity increases during the Working stroke the rate of fuel injection should increase to sustain that maximum working pressure to the desired point. a V

' I have shown in the drawings more or less diagrammatically a four cycle, double-acting, reciprocating engine which'may be operated to carry out my method.

Figure l is a side elevation, and Fig. 2 an end elevation thereof. Fig. 3 is a horizontal section taken through the cylinder and combustion chamber. Fig. 4 is a vertical sectional detail view of one combustion chamber and Fig. 5 a detail elevation of the fuel pump.

1 is the cylinder and 2 the piston which is connected with the engine shaft in the ordinary manner, the piston rod passing through a stuiiing boxand thus forming an expansion chamber at each end of the cylinder as is usual in engines of this class. Each end of the cylinder communicates with a valve chamberfi provided with an air inlet l of' the automatic suction-operated type, air being supplied through an inlet pipe 5 communicating with the atmosphere. Each valve chamber is provided with an exhaust valve 6 communicating with an ex haust passage 7, these valves being raised at proper times by means of levers 8' pivoted on the frame .of the engine and carry ing cam rolls engaging exhaust cams 9 on the cam shaft 10. The cam shaft is driven in the usual manner by skew gears 11 (see Fig. 1) arranged to rotate the cam shaft at one-half the speed of the engine shaft. At

each end of the-cylinder there is also a combustion chamber 12 connecting with the cylinder through a narrow passage 13. The

cylinderis cooled by a water jacket 14 which tends to maintain av moderate work ing temperature therein. The combustion chambers, however, being relied upon to acquire and maintain a temperature substantially higher than that of the cylinder are not provided with Water jackets or other cooling means.

Each combustion chamber 12 is provided with a fuel inlet port 15. Each port is controlled by a governing valve 16 and a timing valve 17. provided with a tapering extremity as shown in Fig. l by which the effective area of its fuel-inlet port 15 may be varied, Each timing valve 17 is disposed annularly about its governing valve and has "a movement independent thereof. The timing valve serves to either open or entirely close the communication between its inlet port and the fuel chamber 19 which surrounds the valve. The governing and timing valve stems pass outwardly through stuffing boxes 18 and are connected with actuating mechanisms as hereinafter described. The fuel chambers 19 are supplied with fuel through The governing valve is pipes 20 connecting them with the fuel pumps.

To prevent overheating of the fuel valves in the chambers 19 these chambers are surrounded by water jackets 21 communicating through pipes 22 with the water jackets of the cylinder or other source of water supply.

The preferred form of fuel pump is shown in detail in Fig. 5. The pump cylinder 23 contains .a piston 24 free to slide lengthwise of the cylinder. 25 is a plunger carrying at its lower end a cam roll which engages a cam 26 on the cam shaft 10. By

connected with a cam lever 31 carrying a' 'cam roll 32 which engages the cam 33 on the cam shaft. The rotation of the cam shaft 10 and the cam 26 causes the plunger 25 to lift the piston 24 periodically to a fixed point near the top of the pump cylinder. It then retreats quickly from the piston 24 leaving it free to yield to pressure applied through the pipe 27. It's retreat is timed to occur at or before the injection of fuel into the combustion. chamber. After its retreat the position of the piston 2 .1: is governed by the pressure of the liquid contained in the pressure chamber 28 and pipe 27 this pressure being secured by the compression of air in the upper part of the pressure chamber 28 which in' turn is controlled by the plunger 30 and also by the fuel feed as below described.

Liquid fuel is supplied to the pump cylinder 23 below the piston 24: from any suitable source of supply, a check valve 34 being provided to permit the entrance of oil upon the raising of the piston 2-l. Upon theopening of the timing valve 17 to admit fuel into'the combustion chamber, the pressure upon. the under side of the piston 2-1 being reduced, the piston 24 is forced downward by the expansion of the air in the pressure chamber 28 and this movement continues until the timing valve is closed, this movement .of the piston forcing the fuel into the combustion chamber. The amplitude of movement of the plunger 25 should be such as to permit a stroke of the free piston 2-igreater than the maximum required in running the engine under full power. Thus the pump is always in condition to supply whatever amount of fuel is required to'be admitted to the combustion chamber through the fuel valves at a predetermined pressure, and leakage of Ql would become less unless there were such' messes fuel past the piston 24 or plunger 25, unless greater in amount, will not afi'ect the operation of the device as it is compensated for by the expansion of the air in the pressure chamber. As the air in the pressure chamber expands its pressure on the liquid below it and in the pipe 27 and hence on the piston a device as the plunger 30 which operates to offset the loss of air pressure and thus maintain or rather increase the pressure at which the fuel is injected during the period of inj ection. This pressure should increase rather thandecrease so that as the velocity of the piston in the engine increases during the working stroke the amount of fuel injected will be increased in proportion so as to maintain a uniform working pressure in the cylinder during that portion of the working stroke of the piston in which the fuel is injected. This movement of the plunger 30 to control the increased feed of fuel is effected by giving to the cam 33 a proper design so that during the time of fuel injection which in the engine shown comprises substantially 35? of rotation of the crank shaft, the plunger is so raised as to increase the pressure in the pressure chamber :28 and on the liquid piston 29 in the connection 27 and in the chamber above the free piston A. This cam is thus designed with especial reference to the feeding of the fuel into the cylinder in a. quantity dependent on the speed of the piston stroke and the portion of the stroke during which it is desired to-maintain a substantially constant pressure in the working medium.

The means for controlling the fuel valves 16 and 17 is shown particularly in Figs. 1 and 2. The timing valves 17 are pivotally connected with bell crank levers 35 journaled at 36 on thebracket or arm secured to the frame of the engine, the bell crank levers at their lower ends carrying cam rolis 37 engaging cams on the cam shaft 10, the cams being timed to open the timing valves substantially at the beginning of the working stroke of the piston, and to release them after about 85 of rotation of the crank shaft. The timing valves are closed by compressionsprings 38 (Fig. 2). The governing valves are connected to the bent levers 39 on a rock shaft 40 journaled on the bracket secured to the base of the engine, the horizontal arm 41 of said levers being connected with a. vertical stem 42 which is connected with a governor 48 of ordinary form. The governor is rotated by skew gears 44 from the cam shaft 10. By this arrangement the governing valves are opened more or less, according to the speed of the engine.

During the normal operation of the en gine the heat of combustion is sufficient to maintain the combustion chamber at the propc" temperature, but special devices are necessary in starting the engine when the combustion chambers are cold, and for this purpose each combustion chamber is provided with an inwardly-extending thimbleshaped projection L5 which is hollow and may be heated from without by any suitable burner.

The operation of an engine when carrying out my method is as follows: Supposing the piston to be in its inward position, upon its first outstroke air is drawn through the inlet valve into the cylinder. Upon the succeeding instrokc of the piston this air is compressed, a largepart of it being forced into the combustion chamber, since the piston as shown is arranged to have only a slight clearance from the cylinder head. This compression of the air of necessity raises the temperature somewhat, but as only a moderate pressure of piston compression may be used, the air in the cylinder is not thereby heated to a high degree. The air in the combustion chamber, however, receives a substantial accession of heat from the hot walls thereof sufficient to cause ignition of the fuel when the fuel is injected. Upon or after the completion of this compression stroke the timing valve is opened, and the pump operates to inject a stream or spray of liquid fuel into the heated air in the combustion chamber. The fuel is injected into the body of air in the combustion chamber and ignited before it can come in contact with'any surface, which results in complete combustion of the fuel without any. deposit or residue. This injection of fuel commences at substantially the end of the compression stroke, and may last during any desired portion of the succeeding outstroke or working stroke of the piston, according to the control of the fuel supply, thereby securing a comparatively low initial pressure and sustaining it during any desired part of the working stroke with a resulting high average pressure.

lVhat I claim as my invention is l. The method of operating an engine which consists in introducing the fuel into the working medium in any desired increasing quantity during the first portion of the working stroke of the piston, substantially as described.

A method of operating internal combustion engines which consists in confining air in a combustion chamber heated to av temperature above the temperature of ignition of the fuel whereby said air will be heated sufiiciently to ignite fuel, and introducing the fuel into said air in any desired increasing quantity during the. first portion of the working stroke of the piston whereby any desired maximum Working pressure iney be secured and maintained during the Working pressure on the piston will remain introduction of the fuel. substantially '-constant during the first por- 1a 3. Themethod of operating an engine -'tion of the piston stroke. which consists in injecting the fuel into the EDNARD T YOUNG working medium in any desired increasing quantity and under any desired increasing In the presence ofpressure during the first portion of the EDWARD E. BADGER, working stroke of the piston, whereby the GEORGE O. G. COALE.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. (2. 

